Blade fastenings are usually used for the fastening of rotor blades on a rotor of a turbomachine, especially a steam turbine. As a result of the comparatively fast rotation of the rotor, the rotor blades which are arranged on the rotor are exposed to high centrifugal forces. The turbine blade root of the turbine blades must therefore withstand high forces and is pushed radially outward in the blade groove. In addition to the centrifugal forces, severe vibrational loads present a further problem which can result in mechanical damage, material fatigue, corrosion and a migratory movement of the blade root inside the blade groove. For fixing the turbine blade root inside the blade groove, various solutions, such as metal wedges, spring rings or sealing pieces, are known. Metal wedges certainly create a locking of the associated blade root inside a blade groove both axially and radially, but in the case of large rotor blades it is difficult to create sufficient retaining forces with such metal wedges during rotation in the radial direction. Disk springs create only radial retaining forces and necessitate additional expenditure for locking in the axial direction of the associated blade groove. Furthermore, complex measurements are necessary for disk springs during installation. As sealing pieces, provision must always be made for two parts, the installation of which, moreover, partially necessitates the machining of the parts by hand.